Microsoft.Net Framework 3.5 install failure

I've tried installing this priority update several times and get the same
failure error. I'm running WinXP W/sp3. The following failure information was
taken from the "WindowsUpdate.Log". The Windows Defender updated successfully
prior to this one failing.

Failure Content Install Installation Failure: Windows failed to install the
following update with error 0x80070643: Microsoft .NET Framework 3.5 Service
Pack 1 and .NET Framework 3.5 Family Update for .NET versions 2.0 through 3.5
(KB951847) x86.

You receive error code 0x80070643 or error code 0x643 when you use the
Windows Update or Microsoft Update Web sites to install updates
http://support.microsoft.com/kb/958052

Maybe this can help:

You receive error code 0x80070643 or error code 0x643 when you use the
Windows Update or Microsoft Update Web sites to install updates
<http://support.microsoft.com/default.aspx/kb/958052>

and /or

How to troubleshoot common Windows Update, Microsoft Update, and Windows
Server Update Services installation issues

<http://support.microsoft.com/default.aspx/kb/906602>

When you try to install an update for the .NET Framework 1.0, 1.1, 2.0, 3.0,
or 3.5, you may receive Windows Update error code "0x643" or Windows
Installer error code "1603":
http://support.microsoft.com/kb/923100

1. Before doing anything else, write down the .NET Framework versions which
are already installed:

How to determine which versions of the .NET Framework are installed and
whether service packs have been applied
http://support.microsoft.com/kb/318785

2. Now see Resolution Method 2 in http://support.microsoft.com/kb/923100
(ignore the title). After running the appropriate/needed tool, (re)install
all .NET Framework versions manually using the download links on the page.

Just a note to let you know I'm still working the update problem...I've tried
the first two suggestions and come up with the same results. J.S. I ran the
two reg progs and reviewed the log, however it really didn't make a lot of
sense to me. I read through it and did not note any error codes. I could post
the log here if that would be appropriate. It's getting pretty late so I'm
going to pick up on Pa Bears suggestion to uninstall and reinstall the net
family tomorrow. I currently have 1.14322.2407 and 2.0.50727.1433 installed.

..NET Framework Setup Verification Tool User's Guide
http://blogs.msdn.com/astebner/pages/8999004.aspx

Automated cleanup tool to remove
the .NET Framework 1.0, 1.1, 2.0, 3.0 and 3.5
http://blogs.msdn.com/astebner/archi...30/611355.aspx

The Cleanup Tool is the Verification Tool is not,
so I just posted them both. Take note that even the
Cleanup Tool leaves a few scraps around.

AH-hah... so - it's NOT my fault. wpheeew
BUT... it LOOKS like a dam7d complicated rigmarol to FIX a supposedly simple
auto fix? HELLO MACRO HARD (Ur mini is_softer & Ur micro doesn't even have
one?)
WHY DOESN'T THE TECIES actually do something about this... I HAVE THE SAME
PROBLEM - but DEFENDER CRASHED & BURNED HORRIDLY (maybe because I always
turn my pc OFF at the wall plug - whever I venture away from the PC?

And - I for one am NOT going INTO the dam7d inards of this complicated
machinery- to FIX something that a DEDICATED HIGHLY TECHNICAL WHIZZKID at
mini flag? CANNOT DO?

p.s...
Both the useless "Defender_Update & this .NET_Update failed" (totally)
PLUS between them - they DESTROYED my systems_restore FUNCTION... as it NOW
REFUSES TO WORK?
PLUS I got not only one but TWO error codes - for FOUR (or was that five)
FAILURES...

Installation Failure

Error Code: 0x643
Try to install the update again, or request help from one of the following
resources.

For self-help options:

Frequently Asked Questions
Find Solutions
Windows Update Newsgroup

For assisted support options:

Microsoft Online Assisted Support (no-cost for issues related to getting
updates)

Print | Close

Installation Failure

Error Code: 0x644
Try to install the update again, or request help from one of the following
resources.

For self-help options:

Frequently Asked Questions
Find Solutions
Windows Update Newsgroup

For assisted support options:

Microsoft Online Assisted Support (no-cost for issues related to getting
updates)

Print | CloseTHING

0x80070643 is a generic error code that is useless without some context.
For a generic fix for it, see:

When you try to install an update for the .NET Framework 1.0, 1.1, 2.0,
3.0, or 3.5, you may receive Windows Update error code "0x643" or
Windows Installer error code "1603"
http://support.microsoft.com/kb/923100

" Windows Update error code "0x643" and Windows Installer error code
"1603" are generic error codes. Typically, these error codes mean that
the update was not installed. These errors codes are usually caused by a
corruption in the .NET Framework installation or by an inconsistency on
the MSI database state. "